The present invention relates to an oxygen and moisture impermeable coextruded or coated multilayer barrier film, and to articles produced therefrom including ostomy bags and heat sealable bags for packaging a variety of materials.
Plastic film laminates having oxygen and moisture vapor barrier properties are desirable for current packaging requirements, as well as for use in medical applications such as the fabrication of ostomy bags. Such films have been provided through the use of multi-ply film laminates where at least one of the plies is oxygen and moisture vapor impermeable. Typically, the films comprise chlorinated polyethylene films or plasticized polyvinyl chloride films, polyvinylidene chloride copolymer films, or multilayered structures such as ethylene vinyl acetate-polyvinylidene chloride/ethylene vinyl acetate combination films. Such constructions adequately meet the needs of oxygen and moisture barrier properties, but in use are often difficult to dispose of in a manner convenient to the user, such as by flushing the bag down a toilet.
Martini et al, U.S. Pat. No. 4,906,495, relate to a laminated film used for ostomy applications. The barrier and water soluble layers must be glued together using an additional adhesive layer. Such additional layers not only add to materials and manufacturing costs, but also result in a thicker film laminate having greater stiffness.
Both Brooks et al, U.S. Pat. No. 4,772,279, and Coombes, U.S. Pat. No. 4,917,689, relate to disposable ostomy bags having an outer water soluble layer of polyvinyl alcohol and an inner relatively insoluble layer of polyvinylidene chloride. Likewise, United Kingdom Patent Nos. 2,083,762 and 2,193,925 both show disposable ostomy bags which include a water soluble layer and a barrier layer.
However, many of the current prior art multilayer films do not have heat sealable surfaces, and thus, require complex processes for the fabrication of bags, such as positioning the barrier layer on only a portion of the film. Moreover, many require adhesives to laminate the layers so that they hold together. Accordingly, the need still exists for multilayer barrier films which may be produced by simpler and less expensive conventional processes without the need for additional adhesive layers and lamination steps and for films which are impermeable to moisture and oxygen, provide odor barrier, and which have a heat sealable surface for forming bags or the like.